This invention relates to apparatus for the collection and assay of analytes in oral or other fluids. The invention relates further to a method for the controlled transfer of oral fluid from a collection device to a test cartridge, and to apparatus including a transportation vial for the secure transportation of a sample of oral fluid to a laboratory for test verification.
Bodily fluids such as blood, urine or oral fluid have traditionally been used for the purpose of testing for the presence of particular analytes such as drugs, hormones, pollutants, viral and bacterial antigens in the body. Oral fluid is the term used to describe all of the fluids that can be found in the mouth cavity. It is commonly referred to as saliva but is in fact composed of a number of other components such as bacteria, food debris, enzymes, water, salts and mucoprotein in addition to saliva. The use of oral fluid for analyte testing has a number distinct advantages over other biological fluids. It is a painless, non-invasive technique and the collection is straightforward, can be performed by the donor, and is easily observed. Oral fluid is becoming increasingly used as a sample matrix for testing of substances such as drugs of abuse, infectious diseases and for DNA testing.
For many organisations, drug testing is an important and necessary duty. Police officers for example may wish to conduct roadside tests to determine whether a motorist has taken an illegal substance that will affect his driving capabilities. The criminal justice system often conducts random drug tests on prison inmates, detainees or individuals on probation in order to monitor the presence of illegal drugs. Similarly, sporting authorities may wish to conduct random tests on athletes to detect the presence of performance-enhancing drugs. These and other applications may require testing for the presence of drugs such as cannabinoids, amphetamine, cocaine, opiates, benzodiazepines, methadone, methamphetamine and phencyclidine amongst others.
A number of prior systems for the collection of oral fluid have been developed, most of which rely on a collection device made from an absorbent material which is placed in the mouth. One prior system for example uses a rayon ball which is placed in the mouth for a certain period of time. The ball is subsequently placed into a syringe mechanism to extract the absorbed oral fluid prior to testing. This system suffers from the disadvantage that it is difficult to know when an adequately-sized sample has been obtained, and a subjective judgement is required by the operator to decide when a sufficient volume of fluid has been collected. This results in considerable variation in volume of oral fluid collected and may affect the consistency and reliability of testing. For example, if an insufficient (and undefined) volume of oral fluid is used for testing, then the quantity of any compound present in the sample may be too small to detect.
Another system draws oral fluid from the mouth by osmotic pressure into a small plastic sack consisting of a semi-permeable membrane containing high molecular weight sugars. This system suffers the disadvantage that it may take between 10 to 15 minutes to collect a sufficient volume of oral fluid. This problem is compounded in the case of drug addicts who often suffer from dry mouths and for whom collection of an adequate volume of oral fluid make take an inordinate length of time.
A further system uses an aspirator to draw and de-bubble oral fluid directly from the mouth into a test cartridge housed in an instrument casing. This system suffers the drawback that it is large, cumbersome and lacks portability.
Our International Patent Application WO00/04381 (and US Patent Application 2001/0034068 based thereon) describes a system which uses an absorbent foam pad on an indicator handle which turns blue to signal that a sufficient volume of oral fluid has been collected. The collection pad is inserted into a tube having a separator filter to extract oral fluid from the pad which is then transferred to a test cartridge by carefully pipetting a number of drops onto the cartridge. The ease in maintaining reliability of testing using this system may however be significantly reduced if collection takes place in a turbulent environment, for example by the roadside.
Further examples of prior systems are described in the following patent applications. The device described in international patent application WO 01/49820 comprises an absorbent foam swab having a tether which is placed into a port of a testing device The tether may be used to pull and compress the foam swab thereby transferring a volume of fluid from the swab to a test strip or a sample container. U.S. Pat. No. 4,580,577 describes a device having an absorbent mass which is placed in a chamber and compressed by a piston screwed down into the chamber. Fluid is thereby transferred from the absorbent mass to a collection vial. European Patent Application 0 734 686 describes an oral fluid sample collection device comprising an absorbent cotton pad on a plastic handle with a colour dye sample adequacy indicator. U.S. Pat. No. 6,303,081 describes a collection device incorporating a bite plate in which oral fluid is drawn by capillary action from the mouth, through a wick to a chromatography strip. United States Patent Application 2002/0015663 describes a syringe mechanism to transfer oral fluid from the mouth to a test strip. Another collection system is described in U.S. Pat. No. 5,335,673.
In view of the disadvantages of prior systems, we have appreciated the need for a non-invasive system for the collection and testing of oral fluid which is portable, quick and easy to use. We have further appreciated the need to eliminate subjective judgement and reduce errors on the part of the operator to enable the system to produce reliable, reproducible and consistent results. Furthermore, we have appreciated the need to allow point-of-care (on-site) collection and testing with the option of sending the collected specimen to a laboratory for further testing or the option of sending the collected sample directly to a laboratory without an on-site analysis.